Table 3.
Effect of CPAP on aldosterone levels.
| Author | Nation | Study design | Number (male) | With HTN? | Follow-up (months) | Compliance (h/night) | Outcome |
|---|---|---|---|---|---|---|---|
| Nicholl (26) | Canada | Observational | 30 (20) | Normotensive | 1 | >4 | PAC ↓ |
| Nicholl (28) | Canada | Observational | 20 (15) | Normotensive | 1 | >4 | PAC ↓ |
| Møller (29) | Denmark | Observational | 13 (12) | Normotensive | 14 | Sufficient compliance | PAC, PRA, Ang II → |
| Meston (33) | Britain | RCT | 101 (101) | No data | 1 | Placebo: 4.6 ± 2.4; active: 5.4 ± 1.6 | PAC ↑ in both groups and sham/active differences → |
| Joyeux-Faure (34) | Spain | RCT | 37 (32) | RHTN | 3 | CPAP: 3.90; sham CPAP: 1.86 | Increase of PAC was significant in the sham CPAP group compared with active CPAP; renin → |
| De Souza (25) | Brazil | RCT | 117 (47) | RHTN | 6 | >4 (45 patients in the CPAP group meet good compliance) | 24-h UAldo |
| ↓ solely in patients with true RHTN, but not in those with whitecoat RHTN | |||||||
| Sánchez-de-la-Torre (27) | Spain | Observational | 37 (37) | RHTN | 3 | >4 | PAC → |
| Decrease of ARR was significantly greater in the responder group (n = 18) | |||||||
| Lloberes (32) | Spain | RCT | 78 (59) | RHTN | 3 | 5.6 ± 1.5 | PAC ↓ was found in nine patients with whitecoat RHTN, but not in the 27 patients with true RHTN |
| Pedrosa (31) | Brazil | Randomized | 35 (27) | RHTN | 6 | 6.01 ± 0.20 | PAC → |
| Saarelainen (30) | Finland | Observational | 11 (11) | HTN | 3 | >4 | PAC ↓, renin → |
OSA, obstructive sleep apnea; HTN, hypertension; RHTN, resistant hypertension; AHI, apnea–hypopnea index; BP, blood pressure; PAC, plasma aldosterone concentration; PRA, plasma renin activity; CPAP, continuous positive airway pressure; RCT, randomized controlled trial; ARR, aldosterone-to-renin ratio; UAldo, urine aldosterone; Ang Ⅱ, angiotensin Ⅱ; ↑, significantly increase; ↓, significantly decrease; →, insignificant change.